This invention relates to safety restraints, and particularly to improvements in safety restraints for high performance vehicles such as racing automobiles, to prevent, or at least minimize, head and neck injuries.
In automobile racing, at speeds in the neighborhood of 100 to 200 miles per hour or more, even glancing impacts can result in serious injuries to drivers or death. Because of the inertia of the driver""s head, in a head-on or side impact collision, the sudden acceleration of the vehicle can cause head injuries due to direct impact of the driver""s head with vehicle parts, and also neck injuries due to sudden and severe bending of the driver""s neck. Efforts have been made to alleviate the problem of head and neck injuries, by restraining the driver""s head movement relative to his body. Examples of restraining devices designed to restrain the driver""s head movement relative to his body are described in U.S. Pat. No. 5,272,770 (Allen et al.) and U.S. Pat. No. 6,009,566 (Hubbard). The Allen et al. and Hubbard devices utilize yokes worn on the driver""s shoulders and one or more attachments connecting the helmet to the yoke. Other head restraining devices, designed primarily for aircraft use, but incorporating features applicable as well to automobile racing, are described in U.S. Pat. No. 4,477,041 (Dunne), U.S. Pat. No. 4,664,341 (Cummings), U.S. Pat. No. 5,267,708 (Monson et al.), U.S. Pat. No. 4,909,459 (Patterson) and U.S. Pat. No. 5,261,125 (Cartwright et al.).
Although devices utilizing yokes have been effective in reducing head and neck injuries, a substantial number of drivers have chosen not to use them. One reason is that they are difficult to remove, and rapid removal can be critical in the case of a crash involving a fire. Another reason is that the yoke is uncomfortable, especially at the high temperatures encountered in the cockpit of a racing automobile. Still another reason for drivers"" resistance to the use of restraint devices utilizing shoulder-worn yokes is that they either prevent, or excessively restrict, rotation of the driver""s head about an axis aligned with the cervical vertebrae and extending in the cranial-caudal direction, and thereby limit the driver""s effective range of vision to approximately 180xc2x0 in a horizontal plane.
Other restraints, which connect the driver""s helmet to the seat or to other parts of the vehicle are subject to one or more of the above-mentioned drawbacks, or are either too complex to be practical in a racing automobile or have only a limited ability to prevent forward tilting of the driver""s head in the case of a head-on collision.
A general object of the invention is to provide a simple, comfortable, and easily used driver""s safety restraint, having improved effectiveness in reducing injuries in a collision.
A preferred driver""s safety restraint in accordance with the invention comprises a helmet to be worn on the driver""s head, the helmet having a rigid shell for covering at least an upper portion of the driver""s head. The rigid shell includes a front portion for covering an upper part of the driver""s forehead. The front portion has a convex, curved exterior, and an upwardly open channel extends across the exterior of the front portion. The rear wall of the channel is preferably constituted by a portion of the convex, curved exterior of the shell. The restraint also includes a flexible strap received in the channel and connected at both ends to the seat. The strap is longitudinally slidable in the channel and limited to a length to permit the driver to rotate his or her head freely about the cranial-caudal axis, while preventing substantial forward tilting of the head. The channel is preferably provided with a projection extending from the rear wall of the channel toward the front wall, but spaced from the front wall of the channel by a distance preferably approximately equal to the thickness of the strap, and from the bottom of the channel by a distance at least equal to the width of the strap. This projection ensures that the strap will not slide out of the channel in a collision, but allows the strap to be removed readily from the channel so that the driver can exit the vehicle rapidly. In a preferred embodiment of the invention, the strap is connected to the seat, at the ends of the strap, by deformable, substantially non-resilient, connecting rings having a high degree of toughness. In a collision, the movement of the driver""s head stretches and deforms the rings, and consequently, the rings serve as shock absorbers, reducing the likelihood of serious injury to the driver in the event of a sudden stop.
The driver""s safety restraint in accordance with the invention affords several notable advantages over previously used safety restraints. The restraining force acts directly on the forehead area of the driver""s helmet, through the center of gravity of the driver""s head, thereby reducing the likelihood of neck injury resulting from sudden forward movement of the driver""s head. The deformable, substantially non-resilient, connecting ring or rings serve as shock absorbers, reducing the magnitude of the force acting on the driver""s head in a collision. The strap of the restraint can slide in the channel on the driver""s helmet, thereby allowing the driver to turn his head freely, and affording a greater range of vision to the driver. The restraint can be removed easily by the driver or by safety personnel, by sliding the strap out of the channel on the helmet past the strap-retaining projection. The length of the strap can be adjusted easily to accommodate the needs of the driver. Moreover, the parts of the adjustment device can be disconnected from each other, to provide an alternative way in which to remove the restraint from the driver. The strap-receiving channel is preferably molded as an integral part of the helmet, thereby simplifying the restraint and eliminating complex snaps, harnesses and the like, which can interfere with the removal of the driver from the vehicle in an emergency. The restraint is also more comfortable to the driver because it eliminates the need for a shoulder-worn yoke.
Other objects, details and advantages of the invention will be apparent from the following detailed description when read in conjunction with the drawings.